如何在silverlight中创建一个xaml文本框只接受最多一个小数点精度的数字

Question

如何在silverlight中创建xaml文本框只接受最多一位小数点精度的数字。我在这个问题How to make a textBox accept only Numbers and just one decimal point in Windows 8中尝试了答案。但它没有用。我怎么能这样做？

Answer 1

你可以写一个这样的函数，

 txtDiscount.KeyDown += new KeyEventHandler(EnsureNumbers);

//仅允许数字的方法，

void EnsureNumbers(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Tab)
        {
            return; 
        }
        bool result =  EnsureDecimalPlaces();
        if (result == false)
        {
            var thisKeyStr = "";
            if (e.PlatformKeyCode == 190 || e.PlatformKeyCode == 110)
            {
                thisKeyStr = ".";
            }
            else
            {
                thisKeyStr = e.Key.ToString().Replace("D", "").Replace("NumPad", "");
            }
            var s = (sender as TextBox).Text + thisKeyStr;
            var rStr = "^[0-9]+[.]?[0-9]*$";
            var r = new Regex(rStr, RegexOptions.IgnoreCase);
            e.Handled = !r.IsMatch(s);
        }
        else
        {
            e.Handled = true;
        }
    }

确保只有1位小数的方法，

  bool EnsureDecimalPlaces()
    {

        string inText = txtDiscount.Text;
        int decPointIndex = inText.IndexOf('.');
        if (decPointIndex < 1 || decPointIndex == 1)
        {
            return false;
        }
        else
            return true;
    }